export type VisualPageIdentity = { route: string; role: string; viewport: string };
export type VisualPageCompletion = VisualPageIdentity & { actualRoute: string };
export type VisualGroupResult = { id: string; status: string };

const pageKey = (page: VisualPageIdentity) => JSON.stringify([page.viewport, page.role, page.route]);

// Only fully audited pages belong in completed; arrival alone is insufficient.
export function visualCoverageProblems(
  planned: VisualPageIdentity[],
  completed: VisualPageCompletion[],
  expectedGroups: string[],
  groups: VisualGroupResult[],
) {
  const problems: string[] = [];
  const plannedKeys = planned.map(pageKey);
  const completedKeys = completed.map(pageKey);
  if (!plannedKeys.length) problems.push("empty-plan");
  if (new Set(plannedKeys).size !== plannedKeys.length) problems.push("duplicate-plan");
  if (new Set(completedKeys).size !== completedKeys.length) problems.push("duplicate-completion");
  if (plannedKeys.some(key => !completedKeys.includes(key))) problems.push("missing-page");
  if (completedKeys.some(key => !plannedKeys.includes(key))) problems.push("unexpected-page");
  if (completed.some(page => page.actualRoute !== page.route)) problems.push("wrong-arrival");
  if (!expectedGroups.length || new Set(expectedGroups).size !== expectedGroups.length) problems.push("invalid-group-plan");
  if (new Set(groups.map(group => group.id)).size !== groups.length) problems.push("duplicate-group");
  if (expectedGroups.some(id => !groups.some(group => group.id === id && group.status === "passed"))) problems.push("incomplete-group");
  if (groups.some(group => !expectedGroups.includes(group.id))) problems.push("unexpected-group");
  return problems;
}